Canine Breast Cancer

"Canine breast cancer are referred to as
neoplastic malignant mammary gland tumors (MGT), which means that they
are cancerous and growing uncontrollably. Mammary tumors in dogs are
among the most common type of tumor found in intact female dogs.
Approximately 50% - 71% of canine mammary tumors are cancerous, with
the other 50% being considered benign or not life threatening. A dogs
prognosis (expected life expectancy is based on the nature of the tumor
including the tumor size, whether the cancer has spread to nearby lymph
nodes and other areas of the body (metastasis), how deep the tumor is
into the tissue and the presence of estrogen receptors (estrogen
receptors in cells can change cell behavior). If tumors are diagnoses
early, and can be successfully removed with surgery, the prognosis is
excellent. A veterinarian may recommend other therapies along with
surgery including chemotherapy.""

Canine Breast Cancer is the most common type of cancer in
female dogs.
Female dogs have five pairs of mammary glands with the possibility of
tumors forming in any one of the glands. Breast cancer can spread from
one glad
to another. Spaying a female dog dramatically reduces the odds of
getting breast cancer if done early in the dog’s life.

Canine breast cancer represents 52% of tumors found in female
dogs and
are seen in dogs that are between the age of 10 and 11. Half of the
dogs with mammary gland tumors will have multiple tumors. Most dogs
with a tumor will see the cancer spread to the lungs in 1 to 2 years.

Breeds that are Susceptible to Canine Breast Cancer or Mammary
Cancer

Spaniels

Terriers

German Shepherds

Toy and Miniature Poodles

Picture of Dog Breast
Cancer
Inflammatory Mammary
Carcinoma in Dog

Diagnosis of Canine Breast Cancer or Canine Mammary Cancer

Your veterinarian will look for visible signs of canine breast
cancer or
mammary
cancer tumors. Signs can include swelling, or soft or hard lumps near
the mammary glands. If tumors are not visible, diagnosis is made when
other symptoms are investigated and a tumor is found to be the cause.

A Fine Needle Aspiration (FSA) test or biopsy is used to take
a tissue
sample for testing prior to the recommendation of surgery. Though rare,
a tumor may look like cancer when in fact it is a benign cyst. The FSA
test will allow for a definitive diagnosis.

Other necessary tests include a CBC, chemistry profile,
urinalysis and
3-view thoracic X-Rays, which help the veterinary oncologist check if
the disease has spread.

Treatment of Canine Breast or Mammary Cancer

Surgery is the most common form of treatment for breast cancer
that has
not spread (lumpectomy, mammectomy, mastectomy). Localized cases use
surgery as a complete cure, the case if the tumor is small and the
margins or the tumor are easily identified and removed. Chemotherapy is
used in more advanced cases. Surgery is recommended in cases
where the cancer has spread to the lymph node.

Consult your veterinarian if you see any lumps near the
mammary glands. It is possible that tumors are benign (non cancerous).
If this is the case, most veterinarians will remove the tumor and then
send to a lab
for a definitive evaluation.

In addition to surgery, your veterinarian may recommend
chemotherapy treatment to make sure that malignant cells (cancer cells
that spread quickly) do not spread to the lungs. Chemotherapy drugs
such as Adriamycin and oral Cytoxan are used. Recently other drugs such
as mitoxantron (Novantrone™) and Adriamycin or Carboplatin (if other
drugs are proving to be ineffective) have been used. One study shows
that the 2-year survival rate for 8 dogs treated
with surgery alone was 29% while the survival rate for 8 dogs treated
with the chemotherapy medications adjuvant 5-fluouracil and
cyclophosphamide was 100%.3

Chemotherapy usually lasts for a span of 6 months with the
number of treatments defendant on the severity of the disease (possibly
4 to 6 per week).

Another approach to possibly extend an intact female dogs life
with canine breast cancer is not not only have the malignant tumor
removed surgically, but to undergo an Ovariohysterectomy
(OHE). Recent studies have shown that the benefit could
result in a 45% increase in the length of survival after treatment1.

Other approaches that are dependent on tumor type and that
should be discussed with your veterinarian include Radiation Therapy,
Estrogen Therapy and the use of Cox-2 Inhibitors

Common supplements that may contribute to a reduced the risk of
breast cancer
include Inositol hexaphosphate and 1-3-beta glucan. Natural
remedies such as C-Caps may be of some help as a supportive therapy during
and after treatment to strengthen healthy cells and reduce the severity
of symptoms. If your dog is recieving chemotherapy or radiation
be sure to check with your veterinarian since anti-oxidants and certain
supplements may inhibit these types of drugs since they strengthen all
types of cells, even those that may be targeted by treatment.

For dogs with large breast tumors (> 3.0 cm), the
prognosis tends to be poor since there is an 80% chance of recurrence
of the tumor within 6 months after canine breast cancer treatment. The
survival rate of dogs with what is termed gross metastasis or
widespread spreading of cancer is 5 months. The overall rate
of 2 year survival is between 75% and 90%2.